Controlling apparatus for use in connection with hydraulic pumps.



A. T. DAWSON &1. HORNE. CONTBOLLING APPARATUS FUR USE IN CONNEQTION WITHHYDRAULIC PUMPS.

APPLICATION FILED MAY 9. 1917.

Patented July 2,1918.

, 3 SHEETS-SHEET I.

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CONTROLLING APPARATUS FOR USE IN CONNECTION WITH HYDRAULIC PUMPS.`APPLICATION FIL'ED MAYB. I9I7.

1 ,270,794. Patented July 2, 1918 a SHEETS-SHEET 2. l

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A. T. DAWSON &1. HORNE.

CONTROLLING APPARATUS FOR USE IN CONNECTION WITH HYDRAULIC PUMPS.

APPLICATION FILED MAI/9.1911.

Patented July 2, 1918.

3 SHEETS-SHEET 3.

/oramews To all whom t may concern:

UNITED STATES PATENT OFFICE.

ARTHUR TREVOR DAWSON, OF WESTMINSTER, AND JAMES HORNE, OF BARROW-IN-FURNESS, ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF WESTMINSTER, ENG-LAND.

CONTROLLING APPARATUS FOR USE IN CONNECTION WITH HYDRAULIC PUMPS.

Application filed May 9, 1917.

Be it known that we, ARTHUR TnEvoR DAWSON and JAMES Hoa-NE, bothsubjects of the King of Great Britain, residing, respectively, atVickers House, Broadway, Westminster, in the county of London, England,and Naval Construction Works, Barrow-in-Furness, in the county ofLancaster, England, have invented certain new and useful Improvements inor Relating to Controlling Apparatus for Use in Connection withHydraulic Pumps, of which the following is a specification. l

This invention relates to controlling apparatus for use in connectionwith hydraulic pumps such as employed for supplying liquid underpressure to presses or other hydraulic motors employed in operatingmachinery, for example heavy gun mountings.

According to this invention lthe motor which drives the pump isautomatically disconnected rom the latter when the demand on thepressure liquid of the pump reaches a predetermined low limit, but isadapted to be automatically connected to the pump when the demand onthe4 pressure liquid increases. For this purpose a hydraulicallyactuated clutch may be provided, the operation of which is dependentupon the pressure of the liquid in the pump system. This invention hasparticular reference to apparatus wherein the pump is operated by anelectric motor the speed of which is automatically controlled inaccordance with the pressure of the liquid in the pump system; a deviceis provided which is responsive to varying Huid pressures which througha suitable switch regulates the speed of the motor from full speed tohalf speed by cutting out the resistance from the field circuit of themotor and from half speed to lowest running speed by insertingresistance in the armature circuit. the said device also being adaptedto actuate a hydraulic valve when the motor is running at its lowestpractical runnin; r speed for allowing the hydraulic clutch to beoperated and so disconnect the electric motor from the pump.

In order that the said invention may be clearly understood and readilycarried into effect we will describe the same more fully with referenceto the accompanying drawings. in which:-

Figure 1 is a general view illustrating Specication of Letters Patent.

Patented July 2, 1918.

Serial No. 167,621.

Fig. 5 is a sectional plan showing on a larger scale than Figs. 3 and la modified form of the means shown in Figs. 1, 3 and 4 for automaticallydisconnecting the electric motor from the pump, and

Fig. 6 is a view similar to Fig. 5 showing still another form ot' thesaid means.

A is the electric motor and A its shaft. B is the pump and B its drivingshaft. The pump may be of the double acting two or three cylinderreciprocatingtype and delivers water under pressure through a pressuremain I) (see Figs. 3 and 4) to the hydraulic motor (not shown) foroperating the machinery to be driven. The pistons or rams of the pumpare actuated by one or more pinions b", b* on the shaft B gearing with atoothed wheel Bx on the crank shaft of the pump. Connected to the mainis a small pipe b which in turn is connected to the lower end of acylinder C containing a spring loaded piston C which can move againstthe action of the springs C under the influence of and to an extentdependent upon the pressure of the liquid in the pipe b. The piston CXis connected by a rocking arm or lever Co to a slide valve C whichcontrols the supply of pressure liquid from the pipe L through a portleading to the lower surface of a motor ram C2 to enable the latter tobe raised in accordance with the pressure of the liquid, the valve alsoenabling the aforesaid port to be placed in communication with anexhaust port leading to the upper part of the ram when the ram descends.Thus the ram moves in accordance with the pressure ot' the liquid in thepump system. This ram carries a rack C3 which is connected throughsuitable gearing such as the pinion and the shaft C, to switch arms D,D: ol these the 'former serves to regulate the speed of the electricmotor from full speed to halt' speed by cutting out resistance from thefield circuit d arranged to move about a common axis, that is to saythey are both mounted on the shaft C5. The means for automaticallydisconnectingthe electric motor A from the pump B comprise a clutch E ofthe multiple plate type controlled by a spring e and operated by ahydraulic ram E working in a cylinder E2 to which pressure liquid isadmitted when the liquid in the pump system reaches a predetermined highpressure, for displacing the ram E into a position to relieve the clutchplates of the pressure of the spring e, thereby enabling the motor A torotate-without actuating the pump B. For this purpose the ram cylinderE2 is connected by a pipe e2 to a clutch control valve arrangedco-axially with respect to the E3 which is normally held by a spring, orby pressure liquid supplied by a branch pipe b2* of the pipe b in itsexhaust position shown in Fig. 1 but which is adapted to be moved by theend of the aforesaid rack C3 in Fig. 1, or by a collar C3* thereon inFig. 3, coming against a tappet e3 (see Fig. l) 'on the valve, oragainst a lever 63X .(see Fig. 3) connected to this valve, in order todisplace the said valve and admit pressure liquid to the ram cylinderE2, thereby relieving and inally removing the pressure of the clutchspringl e from the frictionV plates. -The ram E in Figs. 1, 4 and 5 isshafts A and B- and forms part of or is connected `to a disk einterposed between the clutch spring e and the friction plates. lThe ramcylinder E2 in these igures is formed in a part E4 connected to theshaft B. In Figs. 1 and 4 the'shafts A', B are arranged end t'o end and.the shaft B is formed with an axial conduit B'x communicating at oneend with the ram cylinder E2 and at the other end with the pipe e2. InFig. 5 the shaft A passes axially through the shaft B and the clutch Eis situatedv at the outer end of the shaft A.

In each 'of the examples shown by Figs.-

1, fl and-5 only one electricmotor is employedbut` in Fig. 6 twoelectric motors are used; in this case two clutches E, E are employed,the aforesaid disk e Iof each of the clutches being connected by a levere4 to theram or 'piston E. These two rams or pistons are disposed in asingle cylinder E2 so that when pressure liquid is admitted Ato thecentral portion of the cylinder E2 by the aforesaid pipe e2,`the disks ewill be finoved to relieve the pressure of the springs AIt, on thefriction plates f'of the clutches, fithereby disconnecting the motorssimulta- Vneously from the pump as aforesaid.

-f The aforesaid switch D may be employed for starting the motor ormotors by disconnecting the switch from the rack C, and in The operationofthe apparatus shown on the drawings is as follows Assuming the motorto be running atfull i speed and a demand for full .hydraulic power, thepiston C will be in its lowest position, the springs CXx being capableof holding it against normal pressure. The motor ram C2 will hold thespeed regulating switch at a position for full speed and the clutchcontrol valve slide E3 will allow liquid in the ram cylinder E2 of theclutch E to pass tothe exhaust so that spring e acts on the frictionplates of the clutch thereby transmitting the drive of the motor to thedriving shaft of the pump. When the vdemand for hydraulic power becomesless, the liquid pressure in pipes b and b will gradually rise andacting on the piston C* will yraise motor ram C2 in the mannerpreviously explained and consequently the switch arm will be moved toaposition corresponding to the power required. The clutch control valveE3 will only come into operation when the demand for hydraulic power hasbecome so small that the speed of the motor is at its lowest practicallimit, the said valve being then operated by the motor ram C2 to admitfluid pressure to ram E of the clutch so as to first relieve and finallyrelease the pressure of the springs e from the friction plates, and thusallow the motor to run free until a further demand for hydraulic powerwhen 'the reverse operation takes place.

1 It will, of course, be understood that the operation of the arm D tocut out resistance from the ield circuit of the motor, the operation ofthe arm D to insert resistance in the armature circuit of the motor andthe subsequent operation of the fluid controlled means to throw out,ythe clutch, results in a three step control of the pump so that thespeed of the motor may be reduced initially and then further reduced asthe occasion requires. If this reduction is not sufficient, the motorwill be entirely disconnected from the system but will remain running ata low speed.

What we claim and desire to secure by Letters Patent of the UnitedStates is 1. The combination with a hydraulic pump, of an electric motorfor driving same, means responsive to and actuated by the pressure oftheliquid in the pump system, a switch for controlling the speed of themotor and operated by said means so that the speed of the motor iscontrolled in accordance with the pressure of the liquid, ahydraulically operated clutch for connecting the motor to the pump and adevice operated by said liquid responsive means for allowarmature andfield circuits of the motor, a

ing pressure liquid to actuate said clutch and thus disconnect the motorfrom the pump.

2. The combination with a hydraulic pump, of an electric motor fordriving same, means responsive to and actuated by the pressure of theliquid in the pump system, a regulating device actuated by said meansfor controlling the speed of the motor in accordance with the liquidpressure in the system by controlling resistances in the hydraulicallyoperated clutch for connecting the motor to the pump and a. valveoperated by said liquid responsive means when v the speed of the motorreaches a predetermined low limit for allowing liquid pressure toactuate said clutch and thus disconnect the motor from the pump.

3. The combination with a` hydraulic pump, of an electric motor fordriving the samemeans responsive to'and actuated by the pressure of theliquid in the pump system, a regulating device actuated by said meansfor controlling the Speed of the m0- tor in accordancev with thepressure in the pump system, and comprising two switches one whichregulates the speed of the motor from full speed to half speed bycutting out resistance from the fie d circuit of the motor and the otherfor controlling the ated clutch which normally 3 connects the motor tothe pump and'a valve operated by said liquid responsive means when thespeed of the motorreaches a predetermined low limit for allowing liquidpressure to 'operate said clutch and thus disconnect the motor from thepump.

4. The combination with a hydraulic pump, of an electric motor fordriving same, means responsive to and actuated by the pressure of theliquid in the p'ump system,

a regulating device actuated by 'said meansfor controlling the speed ofthe motor in accordance with the pressure of the liquid in the pumpsystem, a hydraulically operated clutch, a spring acting on said clutchto cause the latter to connect the motor and the pump together, a valveactuated by said liquid responsive means when the speed of the motorreaches a predetermined low limit for allowing pressure liquid to movesaid clutch against the action of the spring to disconnect the motorfrom the ump.

5. The combination with a hydraulic pump of a motor for driving same, aclutch for connecting the motor to the pump, a device for controllingthe speed of motor, a motor actuated by and in accordance with thepressure in the pump system for operating said speed controlling deviceand said clutch.

In testimony whereof we afiii; our signatures.

ARTHUR TREVOR DAWSON. JAMES HORNE.

